Exhaust gas water extraction system

ABSTRACT

An exhaust gas water extraction system includes an evaporator component in a diffusion absorption refrigeration (&#39;DAR″) unit. The system also includes an exhaust gas input duct comprising an input opening to receive exhaust gas from an exhaust gas source. The exhaust gas input duct operates as a heat source to power the DAR. An evaporator heat exchanger is connected to receive the exhaust gas from the exhaust gas input duct. The evaporator heat exchanger is disposed to generate a heat exchange between the evaporator component and the exhaust gas that cools the exhaust gas to below the dew point. A water collection container receives water condensing from the exhaust gas during the heat exchange with the evaporator component.

RELATED APPLICATIONS

This application claims priority to provisional patent application U.S. App. Ser. No. 61/688,546 titled “Water Recovery from Combustion Exhaust,” by Wade Pulliam, Augustus Moore, Conor C. Galligan, Merritt J. Jenkins, and Eric. S. Packer, filed on May 17, 2012, which is incorporated herein by reference. This application also claims priority to provisional patent application U.S. App. Ser. No. 61/752,715 titled “Water from Exhaust Vapor and Ambient Air,” by Claudio Fillipone, filed on Jan. 13, 2013, which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to systems for recovering water from combustion exhaust gas, and more particularly, to systems and methods for recovering water from combustion exhaust gases in a diffusion absorption refrigeration cycle.

BACKGROUND

Military operations typically involve transporting a large number of troops over large distances often in harsh or unfriendly areas. The logistics train to supply the Forward Operating Bases (“FOBs”) can be very expensive in terms of dollars, strategic vulnerability, and lives lost as demonstrated by recent wars in Afghanistan and Iraq. Bulk materials requiring ground transport may have to be moved long distances over poor road systems that may also be under continued assault by enemy forces. Two important bulk quantities that must be moved are fuel and water. The burden in moving both materials can be great.

Water is a particular need that is difficult to meet for troops in the field. Water is not only used for drinking. It is needed for cooking, cleaning, and sanitation systems. A budget of 6-8 gallons of water a day per soldier is typically used in determining logistics. The water is usually delivered by convoy or helicopter at a high cost. The delivery of the water also places additional troops in harms way. Efforts have been made to capture the water lost to the atmosphere by combustion engines, such as engines used to drive power generators or vehicles in the field. Regrettably, for every gallon of fuel burned, a gallon of water is produced, but this water is released with the exhaust into the atmosphere as superheated vapor and lost. Present systems typically involve cooling the water using vapor compression or some other refrigeration methods. Such methods typically require energy, such as electricity or fuel for power. Diffusion Absorption Refrigeration systems have been used to provide the cooling mechanism. However, fuel such as propane, electricity or some other way of generating heat is required as fuel.

in view of the foregoing, there is an ongoing need for a system and method for cooling exhaust gas from combustion engines that require no additional fuel and that are capable of extracting clean potable water from combustion exhaust gases.

BACKGROUND

Military operations typically involve transporting a large number of troops over large distances often in harsh or unfriendly areas. The logistics train to supply the Forward Operating Bases (“FOBs”) can be very expensive in terms of dollars, strategic vulnerability, and lives lost as demonstrated by recent wars in Afghanistan and Iraq. Bulk materials requiring ground transport may have to be moved long distances over poor road systems that may also be under continued assault by enemy forces. Two important bulk quantities that must be moved are fuel and water. The burden in moving both materials can be great.

Water is a particular need that is difficult to meet for troops in the field. Water is not only used for drinking. It is needed for cooking, cleaning, and sanitation systems. A budget of 6-8 gallons of water a day per soldier is typically used in determining logistics. The water is usually delivered by convoy or helicopter at a high cost. The delivery of the water also places additional troops in harms way. Efforts have been made to capture the water lost to the atmosphere by combustion engines, such as engines used to drive power generators or vehicles in the field. Regrettably, for every gallon of fuel burned, a gallon of water is produced, but this water is released with the exhaust into the atmosphere as superheated vapor and lost. Present systems typically involve cooling the water using vapor compression or some other refrigeration methods. Such methods typically require energy, such as electricity or fuel for power. Diffusion Absorption Refrigeration systems have been used to provide the cooling mechanism. However, fuel such as propane, electricity or some other way of generating heat is required as fuel.

In view of the foregoing, there is an ongoing need for a system and method for cooling exhaust gas from combustion engines that require no additional fuel and that are capable of extracting clean potable water from combustion exhaust gases.

SUMMARY

In view of the above, an exhaust gas water extraction system is provided, in an example implementation, an exhaust gas water extraction system includes an evaporator component in a diffusion absorption refrigeration (“DAR”) unit. The system also includes an exhaust gas input duct comprising an input opening to receive exhaust gas from an exhaust gas source. The exhaust gas input duct operates as a heat source to power the DAR. An evaporator heat exchanger is connected to receive the exhaust gas from the exhaust gas input duct. The evaporator heat exchanger is disposed to generate a heat exchange between the evaporator component and the exhaust gas that cools the exhaust gas to below the dew point. A water collection container receives water condensing from the exhaust gas during the heat exchange with the evaporator component.

In an example alternative implementation, the exhaust gas water extraction system further includes an ambient air opening to an evaporator-ambient air heat exchanger to condense water from the ambient air. The water from the ambient air is collected with the condensate from exhaust gas.

In another example alternative implementation, a water purification system may be added to the purify the water collected from the condensation of the water vapor in the exhaust gas.

In another example, a modular exhaust gas water extraction system takes advantage of the integrated heat exchange opportunities in providing fluid pathways for exhaust gases, ambient air, and refrigerant or refrigerant/absorbent binary solutions within a standard size for multiplying modules and for easy transport by standard size carriers already use.

Other devices, apparatus, systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, he within the scope of the invention, and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be better understood by referring to the following figures. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention, in the figures, reference numerals designate corresponding parts throughout the different views.

FIG. 1 is a schematic diagram illustrating operation of an example exhaust gas water extraction system.

FIG. 2 is a schematic diagram illustrating operation of another example exhaust gas water extraction system that includes water extraction from ambient air.

FIG. 3 is a schematic diagram illustrating operation of an example exhaust gas water extraction system that includes water extraction from ambient air and layout optimization for modularity.

FIG. 4 is a perspective view of an example implementation of an exhaust gas water extraction system.

FIGS. 5A and 5B are top cross-sectional views of an example implementation of a multi-section heat exchanger illustrating the use of fins to enhance heat exchange.

FIG. 6 is a schematic drawing illustrating operation of the example exhaust gas water extraction system in FIG. 4.

FIG. 7 is a perspective view of an example implementation of the exhaust gas water extraction system in which modules are multiplied to increases capacity.

FIG. 8 is a perspective view of another example implementation of an exhaust gas water extraction system.

FIG. 9 is a perspective view of an example implementation of the exhaust gas water extraction system in which modules are multiplied to increases capacity.

DETAILED DESCRIPTION

FIG. 1 is a schematic diagram illustrating operation of an example exhaust gas water extraction system 100. The exhaust gas water extraction system 100 includes an exhaust gas input duct 102 that receives hot exhaust gas emitted from an exhaust gas source 101 such as a power generator powered by a combustion engine, a combustion engine that powers a vehicle, or from any suitable and available combustion gas engine. The hot exhaust gas operates as a heat source to power a generator 104 for a diffusion absorption refrigeration (“DAR”) unit. The generator 104 includes a storage tank 108 and a separator 106 forming boiler 108. The exhaust gas input duct 102 provides a path for the hot exhaust gas to pass a heat exchanger 103 having a thermal connection to the boiler through storage tank 108 and separator 106 in the generator 104. The thermal connection is illustrated in FIG. 1 by the heat flow Q_(H) at 107.

The generator 104 drives a DAR cycle using the heat supplied by the hot exhaust gas in a manner known in the art. The storage tank 108 stores hot refrigerant from the boiler 104 and a refrigerant/absorbent solution, which is provided to an absorber 114. The hot refrigerant is provided to a condenser 110, which discharges heat Q_(cond) at 120 as the refrigerant cools. The cooling refrigerant is provided to an evaporator 112 to supply refrigerant that is absorbed by the refrigerant/absorbent solution in the absorber 114 thereby providing the well-known cooling of the refrigerant in the evaporator 112.

The hot exhaust gas is conducted along an exhaust gas fluid path 150 to an evaporator heat exchanger 152. The evaporator heat exchanger 152 provides a cooling of the exhaust gas illustrated by the heat transfer Q_(ev) at 130 into the evaporator 112. The heat transfer Q_(ev) at 130 cools the exhaust gas to below the dew point causing a condensation of water vapor contained in the exhaust gas. The water condensate is extracted by gravity and collected in a water collection container 140.

FIG. 2 is a schematic diagram illustrating operation of another example exhaust gas water extraction system 200 that includes water extraction from ambient air in addition to water extraction from exhaust gas. The exhaust gas water extraction system 200 includes an exhaust gas input duct 202 that receives hot exhaust gas emitted from an exhaust gas source as described above with reference to FIG. 1. The hot exhaust gas operates as a heat source to power a generator 204 for a DAR unit. The generator 204 includes a separator tank 206 and a storage tank 208. The exhaunt gas input duct 202 provides a path for the hot exhaust gas to pass a heat exchanger 218 having a thermal connection to the generator 204. The thermal connection is illustrated in FIG. 2 by the heat flow Q_(H).

The generator 204 drives a DAR cycle using the heat supplied by the hot exhaust gas as described above with reference to FIG. 1. The refrigerant/absorbent solution is provided to an absorber 214. The hot refrigerant is provided to a condenser 210, which discharges heat Q_(cond) at 221 as the refrigerant cools. The cooling refrigerant is provided to an evaporator 212 to supply refrigerant that is absorbed by the refrigerant/absorbent solution in the absorber 214 thereby providing the well-known cooling of the refrigerant in the evaporator 212.

The hot exhaust gas is conducted along an exhaust gas fluid path 250 through a recuperator heat exchanger 240 configured to receive the hot exhaust gas before the exhaust gas is cooled by the evaporator 212. The recuperator heat exchanger 240 also receives cooled exhaust gas to provide a counter-flow heat exchange between the hot exhaust gas and the cooled exhaust gas.

The now pre-cooled exhaust gas is conducted along the exhaust gas fluid path 250 to an evaporator heat exchanger 252. The exhaust gas is conducted along the exhaust gas fluid path 250 through an intercooler 220 disposed between the exhaust gas input duct 202 and the evaporator heat exchanger 252. The intercooler 220 in FIG. 2 may be implemented using a heat exchanger configured to provide a counter-flow heat exchange between cooled ambient air or other fluids and the exhaust gas.

The evaporator heat exchanger 252 provides a cooling of the exhaust gas illustrated by the heat transfer Q_(ev) at 230 into the evaporator 212. The heat transfer Q_(ev) at 230 cools the exhaust gas to below the dew point causing a condensation of water vapor contained in the exhaust gas. The water condensate is extracted by gravity and collected in a water collection container 258. Cooled exhaust gas, or low-thermal signature exhaust, from which water has been extracted may be conducted to the recuperator heat exchanger 240 to pre-cool the hot exhaust gas received from the exhaust gas input duct 202.

Condensate water collected in the water collection container 258 may be conducted to a water purification system 270 comprising a water filtering component configured to extract impurities from the water received from the water collection container 258. The water purification system 270 may include a pump to direct the water from the water collection container to the water filtering component. Alternatively to a pump, the pressure differential required to operate the filters can be provided by the exhaust gases, or by a turbo-pump driven by the exhaust gases. The water filtering component may include filters selected from a group consisting of a particulate filter, a hydrocarbon filter, an activated carbon filter, and any combination thereof. The hydrocarbon filter may include hydrocarbon filtering material selected from a group consisting of a smartsponge, organoclay, poly-pro, and any combination thereof.

The system 200 in FIG. 2 also includes an ambient air input opening 260 configured to receive ambient air. The ambient air is conducted to an air to evaporator heat exchanger 256 disposed to generate a heat exchange Q_(ev2), at 225 between the evaporator 212 and the ambient air that cools the ambient air to below the dew point. An ambient air water duct may be used to receive water condensing from the ambient air during the heat exchange with the evaporator component and to direct the water to the water collection container 258. The cooled dry ambient air remaining after the evaporator heat exchanger 256 may be directed to the intercooler heat exchanger 220 as described above.

FIG. 3 is a schematic diagram illustrating operation of an example exhaust gas water extraction system 300 that includes water extraction from ambient air and layout optimization for modularity. The system 300 in FIG. 3 includes an exhaust gas input duct 302 with an input opening at a top portion and an exhaust gas outlet at a bottom portion to direct the hot exhaust gas into an intercooler 332. The exhaust gas input duct 302 provides heat (Q_(H)) at 307 to a boiler 304. The thermal connection between the hot exhaust gas and refrigerant in a storage tank 308 of boiler 306 may be enhanced using a plurality of boiler heating fins 303. The boiler heating fins 303 may project from the storage tank 306 and boiler 308 into the exhaust gas input duct 302.

The generator 304 drives the DAR cycle as describe above with reference to FIGS. 1 and 2 using a condenser 310, an evaporator 312, and an absorber 314. The evaporator 312 includes two heat exchanger portions: an evaporator air cooling portion 312 a and an evaporator gas cooling portion 312 b. FIG. 3 illustrates the heat Q_(cond) at 320 generated by the condenser 310, the heat Qab at 324 generated by the absorber 314.

The hot exhaust gas enters the intercooler 332 for pre-cooling through a counter-flow heat exchange with cooled dry ambient air. The pre-cooled exhaust gas flows along an exhaust gas flow path 350 to an evaporator heat exchanger, which may be implemented by including a first plurality of evaporator HEX fins 352. The evaporator FLEX fins 352 may be cooled by thermal contact with the evaporator gas cooling portion 312 b to below the dew point. The condensate water extracted by cooling by the evaporator HEX fins 352 is collected at an exhaust gas water collection container 358. The cooled dry exhaust gas passed the evaporator HEX fins 352 flows along path 350 to a cooled gas output after thermal exchange with the inlet hot exhaust gas at 302.

The system 300 in FIG. 3 includes an ambient air opening 360 to permit humid air to enter and flow to a heat exchanger, which may be implemented by a second plurality of evaporator HEX fins 356. The evaporator HEX fins 356 cool the ambient air to below the dew point causing condensation of water contained in the air to drop to a condensate from air water container 362, which may be implemented to be the same as the exhaust gas water collection container 358. The water from either or both of the condensate from air water container 362 and the exhaust gas water collection container 358 may be directed to a water purification system as described above with reference to FIG. 2.

FIG. 4 is a perspective view of an example implementation of an exhaust gas water extraction system 400. The system 400 in FIG. 4 includes a multi-section heat exchanger 402 formed by a first heat exchanger panel 404 a and a second heat exchanger panel (“HEX panel”) 404 b opposite the first HEX panel 404 a. The first and second HEX panels 404 are joined by a top sealing member and a bottom sealing member 424 to form a heat exchanger enclosure (“HEX enclosure”). The top sealing member is not shown in FIG. 4 to permit a view to the detail within the HEX enclosure. The bottom sealing member 424 includes at least one condensate outlet, which is hidden in FIG. 4.

The system 400 in FIG. 4 includes a module housing to enclose the multi-section heat exchanger 402. The module housing is not shown; however, one of ordinary skill in the art would know to implement the module housing as a suitable enclosure in any of a number of ways. The module housing would include an ambient air opening at the top end of the multi-section heat exchanger 402 to provide ambient air flow over outer surfaces of the first and second HEX panels 404 a and 404 b.

The system 400 in FIG. 4 includes an exhaust gas input section 405 extending along a first side of the multi-section heat exchanger 402. The exhaust gas input section 405 includes an exhaust gas duct 406 disposed in the exhaust gas input section 405 with an input opening at a top portion and an exhaust gas outlet 410 at a bottom portion. The input opening receives exhaust gas in at 401 and the exhaust gas outlet 410 connects to the multi-section heat exchanger 402 to flow hot exhaust gas into the HEX enclosure.

The multi-section heat exchanger 402 includes an evaporator heat exchanger section and an intercooler section 418. The evaporator heat exchanger section is formed by an evaporator to gas heat exchanger portion 412 and an evaporator to air heat exchanger portion 413. The evaporator heat exchanger section is defined by an area of the first and second HEX panels cooled by an evaporator-component (see FIG. 3). The evaporator component may include an evaporator conduit forming a refrigerant flow path to an absorber component 414 (shown in FIG. 4 outlined by dashed lines). The evaporator conduit may be extended within the HEX enclosure within the area of the evaporator heat exchanger section to provide a thermal connection to the parts of the first and second HEX panels 404 a and 404 b within the area. The thermal connection cools the HEX panels 404 a and 404 b within the area of the evaporator heat exchanger section to cool both the exhaust gas inside the HEX enclosure and the ambient air flowing along the outer surface of the HEX panels 404 a and 404 b.

The intercooler heat exchanger section 418 provides the mechanism for heat exchange between the cooled air flowing over the HEX panels 404 a and 404 b and the hot exhaust gas coming up from the exhaust gas outlet 410 on the exhaust gas input duct 406. The intercooler section 418 pre-cools the hot exhaust gas as it flows inside the HEX enclosure towards the evaporator heat exchanger section.

The absorber component 414 in FIG. 4 may be implemented by a vessel disposed within finned panels forming a gas-to-air heat exchanger (“HEX”) section 415 along a second side of the multi-section heat exchanger 402 opposite the first side. The HEX enclosure may include openings to the space within the gas-to-air HEX section 415 to provide exhaust gas flow inside and ambient air flow outside the gas-to-air HEX section 415. A condenser component 416 may be implemented by a vessel disposed within the gas-to-air heat exchanger 415. The absorber component 414 and the condenser component 416 may advantageously use the thermal connection with the gas-to-air HEX 415 to optimize the characteristics of the DAR cycle.

The system 400 in FIG. 4 includes a cooled gas duct 430 connected to receive cooled exhaust gas from the HEX enclosure for expulsion into the ambient. The cooled. gas duct 430 in FIG. 4 is shown connected to a recuperator heat exchanger (“HEX”) 428. The recuperator HEX 428 is formed by a cooled gas output tube 431 that surrounds the exhaust gas input duct 406 and provides an opening to the ambient. Alternatively, the hot exhaust gas inletting the system 400 at 406 may he cooled by the colder exhaust gases prior to exiting the HEX enclosure by means of any suitable heat exchanger.

The exhaust gas input section 405, which includes the exhaust gas duct 406, includes a generator 420 configured to drive the DAR cycle. The generator 420 is in thermal connection to a liquid-to-gas heat exchanger to receive heat from the hot exhaust gas in the exhaust gas duct 406 to drive the DAR cycle. The generator 420 may be implemented as shown in FIG. 4 as a generator vessel disposed to exchange thermal energy with the exhaust gas input duct 406. A tin structure, a jacketed or any suitable heat exchanger configuration may be used in the generator 420 to aid the heat transfer. It is noted that the generator 420 implementation shown in FIG. 4 is an example for obtaining the heat transfer to the generator 420. Again, other implementations of heat exchangers may be used as well.

A water collection channel 426 extends along the length of the multi-section heat exchanger 402 to receive water condensing from the exhaust gas and ambient air being cooled by the multi-section heat exchanger 402.

Figures SA and 5B are top cross-sectional views of example implementations of multi-section heat exchangers 500 and 550 illustrating the use of tins to enhance heat exchange. FIGS. 5A and 5B are views into the HEX enclosure of the multi-section heat exchangers 500 and 550.

As shown in FIG. 5A, the multi-section heat exchanger 500 may be formed by a first HEX panel 503 facing the outside of the HEX enclosure and a second HEX panel 504 facing the inside of the HEX enclosure. The first HEX panel 503 may include a plurality of external fins 520 disposed on the surface of the first HEX panel 503 to cool ambient air flowing through channels formed by the fins. The second HEX panel 504 may be in thermal contact with an evaporator conduit 510 carrying cooled refrigerant to the absorber component 414 (in FIG. 4).

As shown in FIG. 5B, the multi-section heat exchanger 550 is formed by a first HEX panel 553 and a second HEX panel 554 forming the HEX enclosure 552. The first HEX panel 553 includes a plurality of fins 580 similar to the tins 520 on the multi-section heat exchanger 500 in FIG. 5A. The second HEX panel 554 also includes a plurality of tins 582 extending out to the other side of the HEX enclosure 552. Air flows over the plurality of fins 580 and 582 on both sides of the HEX enclosure 552. The HEX enclosure 552 may include evaporator conduits 560 that allow cooled refrigerant into the space within the HEX enclosure 552. A plurality of internal fins 582 may be used on the inner surfaces of the HEX panels 553 and 554 to aid the cooling of the HEX panels 553 and 554 by the evaporator conduits 560.

FIG. 6 is a schematic drawing illustrating operation of the example exhaust gas water extraction system in FIG. 4. As shown in FIG. 6, ambient air with humidity enters the multi-section heat exchanger 402 at 602. The evaporator heat exchanger section 413 cools the ambient air at 604. The cooled ambient air provides an air-to-gas heat exchange at the intercooler section 418. The heat exchange with the hot exhaust gas warms the air at the inter cooler section 418 resulting in a warm dry air discharge at 606. Cold ambient air that did not pass the intercooler section 418 rises from the bottom of the gas-to-air HEX section 415 at 608. The cold ambient air exchanges heat with the hotter exhaust gas in the gas-to-air HEX section 415 resulting in hot ambient dry air discharge at 610. The cold ambient air that did not pass the intercooler section 418 also rises from the bottom of the exhaust air input section 405 and is heated by the hot exhaust gas in the section 415 resulting in hot dry ambient air discharge at 610.

FIG. 7 is a perspective view of an example implementation of the exhaust gas water extraction system 700 in which multiple modules 702 are used to increases capacity. The modules 702 include exhaust gas input ducts 704 to receive the hot exhaust gas. A cooled gas output duct 706 is included at each exhaust gas input duct 704. Condensate water from each module 702 is deposited into a corresponding water collection container 720 and may pour out at a water spout 722 on each module 702.

FIG. 8 is a perspective view of another example implementation of an exhaust gas water extraction system 800. The system 800 in FIG. 8 includes a multi-section heat exchanger 802 formed by a first heat exchanger panel 806 a and a second heat exchanger panel (“HEX panel”) 806 b opposite the first HEX panel 806 a. The first and second HEX panels 806 are joined by a top sealing member and a bottom sealing member 822 to form a heat exchanger enclosure (“HEX enclosure”) 804. The top sealing member is not shown in FIG. 8 to permit a view to the detail within the HEX enclosure 804. The bottom sealing member 822 includes at least one condensate outlet, which is hidden in FIG. 8.

The system in FIG. 8 includes the components of the DAR cycle in the HEX enclosure 804 such as an evaporator 812 inside the HEX enclosure 804 as described above with reference to FIG. 4. The evaporator 812 forms an evaporator HEX section 813 as described above with reference to FIG. 4. An intercooler HEX section 818 is also provided on the lower portion of the multi-section heat exchanger 802.

Hot exhaust gas enters the system 800 at an input opening of an exhaust gas input duct 801. The exhaust gas input duct 801 may pass a liquid to gas heat exchanger to provide thermal contact with a generator as described above with reference to FIG. 4. The hot exhaust gas may then be conducted into the multi-section heat exchanger 802 where it is cooled to condense the water vapors in the exhaust gas. The water condenses and flows into a water collection container 824.

The system 800 also includes a gas-to-air HEX section 815 along a second side of the multi-section heat exchanger 802 opposite the first side. The gas-to-air HEX section 815 includes a cooled gas duct connected to a cooled exhaust gas opening to the HEX enclosure 804. The cooled gas duct connects to the cooled exhaust gas opening and extends to an opening 810 in a top side of the gas-to-air HEX section 815.

FIG. 9 is a perspective view of an example implementation of the exhaust gas water extraction system 900 in which modules are multiplied to increases capacity. The system 900 in FIG. 9 includes multiple modules 902 each comprising corresponding exhaust input gas sections 904 and cooled gas output sections 906. A header 910 is provided with a hydraulic connection to each opening of each exhaust gas input section 904. The header 910 provides a single connection to a combustion exhaust gas source for all of the modules 902. The water condensate for each module 902 is collected at a corresponding bottom sealed panel 915. Water is transferred to a water collection container 924 to enable pouring the water to a corresponding water spout 922. The water spouts 922 may pour into another common container (not shown), which may then direct the water to a water purification system.

Other devices, apparatus, systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. 

What is claimed is:
 1. An exhaust gas water extraction system comprising: an evaporator component in a diffusion absorption refrigeration (“DAR”) unit; an exhaust gas input duct comprising an input opening to receive a hot exhaust gas from an exhaust gas source, the exhaust gas input duct configured to operate as a heat source to power the DAR; an evaporator heat exchanger connected to receive the exhaust gas from the exhaust gas input duct and disposed to generate a heat exchange between the evaporator component and the exhaust gas to cool the exhaust gas to below the dew point; and a water collection container disposed to receive water condensing from the exhaust gas during the heat exchange with the evaporator component.
 2. The exhaust gas water extraction system of claim 1 further comprising an intercooler disposed between the exhaust gas input duct and the evaporator heat exchanger.
 3. The exhaust gas water extraction system of claim 2 where the intercooler comprises a gas-to-air heat exchanger.
 4. The exhaust gas water extraction system of claim 1 further comprising: a cooled exhaust gas output duct configured to receive cooled exhaust gas after the exhaust gas has been cooled by the evaporator component and to provide a flow path for the cooled exhaust gas; and a recuperator heat exchanger configured to receive exhaust gas before the exhaust gas is cooled by the evaporator component and to receive the cooled exhaust gas, the recuperator heat exchanger configured to provide a counter-flow heat exchange between the hot exhaust gas and the cooled exhaust gas.
 5. The exhaust gas water extraction system of claim I further comprising: an ambient air input duct configured to receive ambient air; an air to evaporator heat exchanger connected to receive the ambient air from the ambient air input duct and disposed to generate a heat exchange between the evaporator component and the ambient air that cools the ambient air to below the dew point; an ambient air water duct connected to receive water condensing from the ambient air during the heat exchange with the evaporator component and to direct the condensed water to the water collection container.
 6. The exhaust gas water extraction system of claim 5 further comprising: an intercooler configured to receive the hot exhaust gas before the evaporator component and the cooled ambient air, the intercooler configured to provide a counter-flow heat exchange between the cooled ambient air and the hot exhaust gas.
 7. An exhaust gas water extraction module comprising: a multi-section heat exchanger formed by a first heat exchanger panel and a second heat exchanger panel (“HEX panel”) opposite the first HEX panel, the first and second HEX panels being joined by a top sealing member and a bottom sealing member to form a heat exchanger enclosure (“HEX enclosure”), the bottom sealing member comprising at least one water outlet; a module housing to enclose the multi-section heat exchanger, the module housing comprising an ambient air opening at the top end of the multi-section heat exchanger to provide ambient air flow over outer surfaces of the first and second HEX panels; a exhaust gas input section extending along a first side of the multi-section heat exchanger, the exhaust gas input section comprising an exhaust gas duct disposed in the exhaust gas input section with an input opening at a top portion and an exhaust gas outlet at a bottom portion, where the input opening receives exhaust gas and the exhaust gas outlet connects to the multi-section heat exchanger to flow into the HEX enclosure; a cooled gas duct connected to receive cooled exhaust gas from the HEX enclosure for expulsion into the ambient; an evaporator component in a diffusion absorption refrigeration (“DAR”) unit, the evaporator component comprising an evaporator conduit forming a refrigerant flow path to an absorber component, the evaporator conduit connected at an end opposite the absorber component to receive refrigerant from a condenser containing refrigerant received from a generator that uses the hot exhaust gas as a heat source, the evaporator conduit disposed inside the HEX enclosure to cool an area of the first and second HEX panels defining an evaporator heat exchanger section; an intercooler section formed in a portion of the multi-section heat exchanger to pre-cool the exhaust gas entering from the exhaust gas duct, where ambient air is cooled by the outer surface of the HEX panels at the evaporator heat exchanger section and the intercooler section; and a water collection container extending along the length of the multi-section heat exchanger to receive water from the at least one water outlet condensing from the exhaust gas and ambient air being cooled by the multi-section heat exchanger.
 8. The exhaust gas water extraction module of claim 7 further comprising: a recuperator heat exchanger (“recuperator HEX”) heat exchanger configured to provide a counter-flow heat exchange between the HOT exhaust gas and the cooled exhaust gas.
 9. The exhaust gas water extraction module of claim 8 where: the recuperator HEX is formed by a cooled gas output tube that surrounds the exhaust gas input duct and provides an opening to the ambient, the cooled gas output tube having a fluid opening to the cooled gas duct, where the cooled gas duct connects to a cooled gas opening in the HEX enclosure.
 10. The exhaust gas water extraction module of claim 7 further comprising: a gas-to-air HEX section along a second side of the multi-section heat exchanger opposite the first side, the gas-to-air HEX section includes a cooled exhaust gas opening to the HEX enclosure, where the cooled gas duct connects to the cooled exhaust gas opening and extends to an opening in a top side of the gas-to-air HEX section.
 11. The exhaust gas water extraction module of claim 7 further comprising: a plurality of ambient air cooling fins distributed substantially across the multi-section heat exchanger to exchange heat with the ambient air.
 12. The exhaust gas water extraction module of claim 7 further comprising: a plurality of exhaust gas cooling fins distributed substantially across the inner surfaces of the HEX enclosure to exchange heat with the exhaust gas.
 13. The exhaust gas water extraction module of claim 7 where: the generator comprises a liquid-to-gas heat exchanger.
 14. The exhaust gas water extraction module of claim 7 where: the generator comprises a generator vessel disposed to surround the exhaust gas input duct in thermal contact with the exhaust gas input duct.
 15. The exhaust gas water extraction module of claim 7 further comprising: a generator-to-exhaust gas heat exchanger (“generator-to-exhaust gas HEX”) configured to transfer heat from the exhaust gas to the generator to drive a DAR cycle.
 16. The exhaust gas water extraction module of claim 15 further comprising: a plurality of generator fins disposed on the generator-to-exhaust gas HEX to conduct the heat to the generator.
 17. The exhaust gas water extraction module of claim 7 further comprising: a water purification system configured to receive condensate water collected via the water collection container, the water purification system comprising a water filtering component configured to extract impurities from the water received from the water collection container.
 18. The exhaust gas water extraction module of claim 17 where the water purification system comprises a pump to direct the water from the water collection container to the water filtering component.
 19. The exhaust gas water extraction module of claim 18 where the water filtering component comprising filters selected from a group consisting of a particulate filter, a hydrocarbon filter, an activated carbon filter, and any combination thereof.
 20. The exhaust gas water extraction module of claim 19 where the hydrocarbon filter comprises hydrocarbon filtering material selected from a group consisting of a smartsponge, organoclay, poly-pro, and any combination thereof.
 21. The exhaust gas water extraction module of claim 7 where the module housing is configured to contain a plurality of multi-section heat exchangers, a plurality of exhaust gas input panels corresponding to the multi-section heat exchangers, and a plurality of cooled gas ducts corresponding to the multi-section heat exchangers.
 22. The exhaust gas water extraction module of claim 21 further comprising a exhaust gas header configured to receive exhaust gas from an exhaust gas source, the exhaust gas header comprising gas ducts connected to the input openings of the exhaust gas input ducts of each of the plurality of exhaust gas input panels.
 23. The exhaust gas water extraction module of claim 22 further comprising: a water purification system configured to receive water collected via the water collection container, the water purification system comprising a water filtering component configured to extract impurities from the water received from the water collection container.
 24. The exhaust gas water extraction module of claim 23 where the water purification system comprises a pump to direct the water from the water collection container to the water filtering component.
 25. The exhaust gas water extraction module of claim 24 where the water filtering component comprising filters selected from a group consisting of a particulate filter, a hydrocarbon filter, an activated carbon filter, and any combination thereof.
 26. The exhaust gas water extraction module of claim 25 where the hydrocarbon filter comprises hydrocarbon filtering material selected from a group consisting of a smartsponge, organoclay, poly-pro, and any combination thereof.
 27. A method for extracting water from exhaust gas comprising: inputting the exhaust gas from a hot exhaust gas source into an exhaust gas input duct; transferring heat from the exhaust gas to a generator of a diffusion absorption refrigeration (“DAR”) cycle; flowing the exhaust gas through an evaporator heat exchanger using an evaporator component of the DAR to cool the exhaust gas to below the dew point; and collecting condensate from the cooling of the exhaust gas.
 28. The method of claim 27 further comprising: inputting ambient air from an ambient air opening; flowing the ambient air through an evaporator-ambient air heat exchanger to cool the ambient air to below the dew point; and collecting condensate from the cooling of the exhaust gas.
 29. The method of claim 27 further comprising: flowing water collected as condensate to a water purification system to purify the condensate for use as drinking water. 